Abstract: Disclosed is a system for precisely locating a cambered ceramic core within the cavity of an injection molding die, such as is used to form patterns for lost wax method casting of gas turbine airfoils. A combination of at least two independent sets of locators are used: one set of at least three is fixed and contacts the periphery of the core while the other set of at least two is movable and engages the centerline of the core. The two sets independently limit the various degrees of core freedom and maintain its position during injection molding. The concave side of the core is preferably contacted by the fixed locators since this biases deviations into the convex side of the part from which excess deviant material is more readily moved.

Abstract: The present invention provides means for the improved positioning of a strongback in a pattern mold for formation of expendable patterns thereon. Investment casting molds formed around the assembly of strongback and patterns are characterized as having the strongback precisely and reproducibly suspended therein. Articles, such as turbine blade halves, cast in such investment molds have mating surfaces in close dimensional relationship and can be bonded one to any mating other to form a finished product.In particular, a strongback having bonding locators near the opposite ends thereof is provided with additional locators to be used in suspending the strongback in the pattern mold. According to the invention, these pattern mold locators are colinear with and in close proximity to the bonding locators and are engaged by locating means in the pattern mold for establishing precise positioning of the strongback therein.